Production of thin hot strips of high silicon bearing FeSi-strip using the integrated technology of thin slab casting and hot rolling

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Within the first phase of the project, various hot rolling strategies weredeveloped for the production of a thin, 1 mm thick hot strip of the Fe-2,4 wt.-% Si alloy using the conventional hot rolling process withprevious reheating and the integrated thin slab casting technology.The interactions of the individual process steps and the influence ofthe hot strip on the magnetic properties could be demonstrated. Withboth methods of hot strip production, it is possible to roll different hotstrip structures and textures for hot strip thicknesses between 1 mmand 2.5 mm. The hot strip states like hardened, partially softened andsoftened could be realised. Significant differences in texture withmagnetically advantageous and unfavorable textures were foundacross the strip thickness. The hot rolling process was investigatedexperimentally and simulatively. For this purpose, the hardening andsoftening behavior was investigated experimentally and simulativelydescribed by semi-empirically and physically based models. For aholistic view of the production of non-grain-oriented electrical sheetsand of the continuous process modeling, the modeling of the materialflow and the microstructural development after hot forming is anessential component with the layer model developed at the IMF as thebasis. The influence of the hot strip on the structure of the finalannealed samples and on the magnetic properties was also analyzed.In the second phase, the simulation of the hot rolling process and themicrostructure development during hot rolling as well as theexperimental work will be continued. Aim is to define hot stripstructures for specific applications with defined magnetic properties,to produce them in a targeted manner and to derive applicationorientedhot rolling strategies. Therefore, in cooperation with the othersubprojects of the research group, using an alloy with a high Sicontent (2.8 wt.% Si) is planed. This makes it possible to investigatethe influence of the alloy on the production process, especially hotrolling, the material behavior during hot forming and the effects on themagnetic properties. Based on the findings of the first phase of theproject, a thin hot strip is produced with a favorable initial state for thecold rolling and for the magnetic properties by means of adaptationsof the rolling strategies, whereby the intended hot strip annealingoffers further possibilities of the microstructure setting. The alteredhardening and softening behavior of the alloy with high Si content willbe also taken into account. The submodels of the individual processstages are linked to one another in cooperation with the projectpartners with the aim of experimentally imaging the theoreticallyderived process parameters and producing a non-grain-orientedelectrical sheet adapted to the defined requirements of thedemonstrator.